There are three strips of 520 that have newer pavement on them, laid sometime last summer. They really do make a difference in tire hiss as you drive across them. Assuming traffic is moving in the morning, I get a couple minutes of blessed silence from the road as I drive across asphalt rubber (still the quietest after several months of use), the control section of regular asphalt (always the noisiest, but new enough not to create the roar of older asphalt from other parts of 520), and polymer-extended asphalt (almost as quiet as the asphalt rubber, and seeming to wear a bit better).
I had the geeky good fortune a few weeks ago to follow a department of transportation test car as it traveled eastbound during the morning commute. It had a frame attached to the right side, from which was suspended a pair of microphones that rode only a few short inches from the rear tire. One of the vehicle’s occupants was collecting data on a laptop in the back seat. All in all, it makes the wannabe scientist in me very happy to see things like this.
